Hi rossgurule,
Thanks for reaching out to our community. I understand that you've successfully registered your Chromecast's MAC address and set it up on the required special university network. However, the device now shows as 'offline' in the Google Home app, and you're unable to cast from any streaming service, even when you connect your phone to that same special network. It is my pleasure to assist you with this concern.
Even though you successfully set up the Chromecast, it's immediately showing as offline because of how the special network works. When a university separates devices onto a "special network" or a separate network for registered devices (like the one that requires a MAC address), those devices are almost always isolated from one another to prevent interaction between devices on the network as a security measure.
The problem you're facing is that your Chromecast is on the special isolated network, but your phone or laptop, where you're running the Google Home app and casting from, is on the standard student WiFi network. Since your casting device (phone/laptop) cannot "see" your Chromecast across the two different networks, it reports it as offline and can't send content to it. Even when you switch your phone to the special network, you might still have trouble because those networks often block the multicast traffic that casting relies on.
Feel free to keep us posted if you have more questions or need further assistance.
Best regards,
Virna
